I'm not sure whether there is a certain amount of jesting going on here or not, but it reminds me of a couple of experiences I have had with compasses.
I was once hunting with my Uncle. He died quite a while back and he was a great guy. If he were active today I would love to introduce him to this forum because he was quite a gadget man. I recall that he had an all-steel Estwing hatchet hanging on his belt sometimes, a knife that I now think was a Mora, and he carried a compass. Anyway we were trying to find red deer in a big patch of mature bush in some country that was relatively flat. We were wondering if we were headed in the right direction. I pulled out my compass, found north, and pointed to it. Something didn't seem right... my uncle pulled out his compass and the needle pointed in exactly the opposite direction. It turned out that my compass had somehow changed its polarity.
Another time I was trying to find the old boundary pegs on a big block of land in a scrubby remote area. I had some pegs and landmarks to work with and I took a sighting on some distant landmarks so that I could walk in a straight line trying to find the pegs. I was in an area of what we call mineral belt country. There are some old exploratory copper mine shafts in the area, and I understand that there are traces of a variety of minerals as well. And although I am not a minerologist, the colour of the rocks makes me think that there is a lot of iron around. I was walking down a compass bearing that I had worked out from an old survey map. I had a top quality prismatic compass that my dad had brought home from the Korean war. Over a 200 yard walk, or less, I saw the compass bearing change by maybe six degrees even though I was walking on a straight line. I guess the iron was affecting the compass.
